The Rolling Stones vs. The Beatles was an epic 1960s feud, at least for their fans. But there was one thing the Fab Four had going for them that really made Stones' guitarist Keith Richards jealous, according to Paul McCartney.

“I talked to Keith Richards recently… well, a couple of years ago, and his take on it was: “Man, you were lucky, you guys, you had four lead singers,” McCartney told the Radio Times. "I could sing, John could sing, George could sing and Ringo did numbers that he could sing. So it wasn’t just the front man and the back-up band."

The bands widely viewed as the two greatest acts of the rock era spent the late 1960s trying to outdo each other with ever-more ambitious albums now regarded as masterpieces. But while The Beatles broke up in 1970, the Stones are still together, at least nominally.

Still, The Beatles had a bond that their rivals couldn't match.

Rampaging Rockers and Mad Musicians

“We were an entity," McCartney said. "Mick used to call us the four-headed Monster. We would show up at places all dressed the same.”